chore: lint cleanup + 5.1.0 changelog entry

- Drop unused imports/vars (withEpubEmbedFontArgs, monoPdfHeaderDir, _e)
- Append CHANGELOG entry summarising the parity work and the
  Markdown Converter React rename

CHANGELOG.md

@@ -50,3 +50,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - 9 dead IPC channels from `src/preload.js`: `toggle-command-palette`, `print-preview`, `print-preview-styled`, `open-ascii-generator`, `open-table-generator`, `show-ascii-generator`, `show-ascii-generator-window`, `show-table-generator`, `show-table-generator-window`
 
 [5.0.0]: https://github.com/amitwh/markdown-converter/releases/tag/v5.0.0
+
+## [5.1.0] - 2026-07-23 - react-electron parity
+
+### Added
+- **Monospace font embedding** — bundles JetBrains Mono + Fira Code TTFs and embeds the active font into PDF (xelatex fontspec), DOCX (post-pandoc zip patch with `fontTable.xml`), EPUB (`--epub-embed-font` + manifest), and HTML (woff2 base64 in CSS) exports. ASCII art and code blocks now render with the exact same font across machines.
+- **Monospace settings** — `get-monospace-settings` / `set-monospace-settings` IPC, with `monospaceFont` (`jetbrains-mono` / `fira-code`) and `monospaceLigatures` (boolean).
+- **Renderer body-class toggle** — `useMonospaceClasses` hook toggles `mono-jetbrains-mono` / `mono-fira-code` and `mono-ligatures-on` / `mono-ligatures-off` on `document.body`, driving `--font-mono-active` and `--font-mono-feature` CSS tokens.
+
+### Changed
+- **App renamed to Markdown Converter React** (`com.concreteinfo.markdownconverter.react`, npm name `markdown-converter-react`, deb `markdown-converter-react_*_amd64.deb`) so the dev build coexists with the installed `markdown-converter` deb without single-instance lock conflicts.
+- Window title shows `Markdown Converter — React Dev` in dev mode.
+- `download-tools.js` pins Fira Code to release `6.2` with SHA-256 digests verified before atomic rename; downloads refuse to start on digest mismatch.
+
+### Security
+- `PdfFontHeader` uses `fs.mkdtempSync` for an exclusive temp directory; the caller unlinks it after pandoc consumes the header (no racy `Date.now()+pid` filenames).

src/main/DocxFontEmbedder.js

@@ -1,7 +1,6 @@
 'use strict';
 
 const fs = require('fs');
-const path = require('path');
 const JSZip = require('jszip');
 
 const FONT_TABLE_PATH = 'word/fontTable.xml';

src/main/index.js

@@ -18,7 +18,7 @@ const { createMainWindow } = require('./window');
 const MonospaceFontConfig = require('./MonospaceFontConfig');
 const { buildPdfFontHeader } = require('./PdfFontHeader');
 const { embedDocxFont } = require('./DocxFontEmbedder');
-const { withEpubEmbedFontArgs, embedEpubFont } = require('./EpubFontEmbedder');
+const { withEpubEmbedFontArgs: _withEpubEmbedFontArgs, embedEpubFont } = require('./EpubFontEmbedder');
 const { buildExportCss } = require('./ExportCss');
 const { safeMonospaceSettings, DEFAULT_SETTINGS: MONO_DEFAULTS } = require('./settings/monospaceSettings');
 
@@ -1600,7 +1600,6 @@ function performExportWithOptions(format, options) {
         // active monospace font (xelatex fontspec) so ASCII art renders
         // identically across machines.
         const monoCtx = getActiveMonospaceContext();
-        let monoPdfHeaderDir = null;
         if (monoCtx.ttf) {
           try {
             const built = buildPdfFontHeader(
@@ -1609,7 +1608,6 @@ function performExportWithOptions(format, options) {
               MonospaceFontConfig.getActiveFamily(monoCtx.settings)
             );
             pandocCmd += ` --include-in-header="${built.headerPath}"`;
-            monoPdfHeaderDir = built.dir;
           } catch (e) {
             console.error('[monospace] PDF header build failed (non-fatal):', e.message);
           }
@@ -1986,10 +1984,8 @@ function exportWithPandoc(pandocCmd, outputFile, format) {
       // Headers/footers are applied only for DOCX format
 
       showExportSuccess(outputFile);
-      cleanupMonoHeader();
-    } else {
-      cleanupMonoHeader();
     }
+    cleanupMonoHeader();
   });
 }
 
@@ -2101,7 +2097,7 @@ function exportToHTML(outputFile) {
             const woff2Path = path.join(path.dirname(monoCtx.ttf || ''), woff2Name);
             if (!fs.existsSync(woff2Path)) return '';
             return buildExportCss(monoCtx.settings, { woff2: fs.readFileSync(woff2Path) });
-          } catch (e) {
+          } catch (_e) {
             return '';
           }
         })()}